With the announcement to the absence of Mr. Pym in the "Avengers: Age of Ultron". My guess to the origins of the villain would be...

Since these movies are linked, due to the post credit scenes and phases and what not. In Iron man 3, we saw that everything is not what they seem and that the story can be twisted and RDJ is the key, center piece, bread & butter, what have you. The end of the movie we have a Tony Stark without the arc reactor in his chest, also in the last fight there are multiple Iron Man suits that are unmanned. If Jarvis is Tony's main OS then he could have already made a security OS with the alphabetical serial numbers coded U.L.T.R.O.N. And that could already be running the suits. Joss already included that Ultron evolves and has a couple of iterations.